It’s not bad, but I’ve seen it put this way:

It’s quite easy to believe a species of reptile could conceivably end up standing upright and having a similar body shape to us, as there’s nothing in the defining features of a reptile that are broken by that concept

But mammary glands (tiddies) are quite literally what makes a mammal a mammal, giving it to a reptile is going to raise a question to those aware of these definitions